I agree with you ILOVETTATT2
the word CULT isn't a legal term like religion is and it is a term to convey disdain and dislike. JWfacts and Steve Hassan admit to expressing their dislike for the individual groups they have left and that they have built their models based on that.
re mainstream religion, I think they still have branches that satisfy the more strict and authoritarian aspects that people may want to practice and that the religion may want to offer and that are binding within that context.
I agree as well that groups can start of loosely and then when schisms arise within and the group feels threatened they enforce strict guidelines but I don't use the word cult anymore as I am more interested in what constraints the environment offers and how people either live with these or try to shake them off.
edit: this site for example - is it morphing